ALAMEDA, Calif. -- Looking for the catalyst of the Oakland Raiders' massive haul this offseason, a spree in which they landed 20 new players and re-signed 12 of their own while doling out almost $110 million in guaranteed money to four players?

Coach Jon Gruden has an inkling, even if, as he says, it pains him and Khalil Mack fans to say it. Yes, the trade of the All-Pro edge rusher on Sept. 1 in the middle of Mack's holdout netted not only a gaggle of draft picks and salary-cap space, but also some intriguing hardware.

"I'm not going to sit here and say that I didn't cry for three days," Gruden said at last month's NFL owners meetings. "I wanted to coach Mack. And Mack knows it. Wish him the best, but we have a lot of work to do with this football team, and that trade allowed these acquisitions that we're talking about today to even happen."

Yes and no.

Though the move was derided by fans and media alike -- even as Raiders owner Mark Davis later said Mack had broken off communication with the team during the holdout and did not want to return to Oakland despite the team twice offering him a contract that would have made him the highest-paid defensive player in the NFL -- the trade also caught the attention of the Sloan Sports Analytics Conference at MIT. And last month, the group feted the Raiders with the "Best Transaction" award, referring to the Mack trade as the "best move any franchise made in 2018 in any sport" while being lauded by Richard Thaler, the 2017 Nobel Prize winner for economics.

Call the whole thing funny math, because Mack did eventually get the massive contract he wanted from the Chicago Bears, a $141 million deal with $90 million guaranteed -- a record for a defensive player.

Asked about the Best Transaction award, Gruden grimaced.

"I think it was the only award we got last year," he spit out, referencing the Raiders' 4-12 teardown season two years after they went 12-4 and played in the postseason.

"But forget about all that. I don't really have time to worry about who thinks it's right or wrong. We didn't really have much of a choice. If we did come up with the money to make the contract happen last year, we wouldn't have any of these men we're talking about right now."

The Newest Raiders

In adding 20 players, the Raiders have doled out almost $115.5 million in guaranteed money while adding more than 68.6 million against the salary cap for 2019. The following are the newest Raiders -- listed in the order they were acquired this offseason -- with their respective guaranteed money and salary-cap numbers for 2019, in millions.

Pos.

Player

Guaranteed

Salary Cap

WR

Antonio Brown

$30.125

$14.958333

OT

Trent Brown

$36.25

$15.25

WR

Tyrell Williams

$22

$10.1

S

LaMarcus Joyner

$21.3

$9.05

WR

JJ Nelson

$.075

$1.0

DE

Josh Mauro

$.400

$1.4

LB

Vontaze Burfict

$.300

$1.803125

CB

Nevin Lawson

$1.555

$3.05

OL

Jordan Devey

$.065

$.735

QB

Mike Glennon

$1.4

$1.865625

S

Curtis Riley

$.165

$.810

QB

Landry Jones

$0

$.645

RB

Isaiah Crowell

$.300

$1.25

LB

Brandon Marshall

$.350

$1.35

TE

Luke Willson

$.165

$.735

WR

Ryan Grant

$.100

$1.25

DE

Alex Barrett

$0

$.495

S

Jordan Richards

$.145

$.735

WR

DeMornay Pierson-El

$0

$.495

DE

Benson Mayowa

$.750

$1.7

ESPN Stats & Information

Gruden then rattled four names: receiver Antonio Brown, acquired in a trade with the Pittsburgh Steelers and given $30.125 million guaranteed for the remaining three years of his contract; offensive tackle Trent Brown, signed to the richest contract for an offensive lineman in NFL history at $66 million over four years with $36.25 million in guarantees; safety Lamarcus Joyner, who reminds Gruden of Ronde Barber and got a four-year, $42 million deal with $21.3 million guaranteed; and receiver Tyrell Williams, who got a $44 million contract over four years and $22 million guaranteed.

"And we wouldn't have the three first-rounders that we're talking about," Gruden added, talking about their own selection at No. 4 overall, the No. 24 pick thanks to the Mack trade with the Bears, and the No. 27 pick courtesy of the Dallas Cowboys, who sent it to Oakland for receiver Amari Cooper.

"So, you have to consider all of it, like the Nobel Prize winner did, and digest it for yourself."

Draft capital? Oakland has eight picks, with four of them coming in the first 35 selections.

"We needed the draft capital to get younger," Gruden said, "to get young, emerging players ... because we felt we had a lot of needs, and we're doing the best we can to address as many as possible."

The Mack trade netted the Raiders the Bears' first-round picks this year and in 2020, as well as a sixth-round pick this year and a third-rounder in 2020. The Bears acquired Mack, a 2020 second-rounder and a conditional fifth-round pick next year. And after sending a third-rounder and a fifth-rounder to the Steelers for Brown, the Raiders got a fifth-rounder back for sending left guard Kelechi Osemele to the New York Jets last month.

New Raiders general manager Mike Mayock was not yet in the building when the Mack trade went down, so he had to catch up quickly amid the whirlwind of Gruden's Raiders rebuild.

"We kind of feel like we made a difference, at several key positions," Mayock said. "And we think it's going to help us in the draft."

And when it comes to Gruden?

"Coach Gruden is a freaking genius, and it's really fun working with him because ... his energy level just drives me to different energy levels," Mayock said. "And he's exhausting because he's so smart, and he's always ahead of you, and you've got to kind of try to catch up. I come home every night just mentally exhausted, and it's a good thing."

Mayock said the "atypical" security afforded Gruden with a 10-year contract also helps with the rebuild and the message.

"I think it gives us an advantage, I really do, and I think Jon and I can sit there and say, 'OK, what is the best move for the future of this franchise?' without the pressure of a coach worried about getting fired," Mayock said. "And I think that means something."

2019 NFL DRAFT

The 20 new Raiders account for $115.445 million in guaranteed money and combine for more than $68.677 million in cap space for 2019, according to ESPN Stats & Information research.

Mayock said most agents prefer their clients' money be deferred until after the team moves to Nevada, where there is no state income tax. The Raiders still have more than $26.7 million in cap space but need $13 million to $15 million of that for the draft class.

As Gruden said, this part of the rebuild would not have been possible without trading Mack. And Cooper. And Osemele. Or cutting Pro Bowl offensive tackle Donald Penn, backup quarterback AJ McCarron and receiver Jordy Nelson, who was actually given a $3.6 million roster bonus in December for this season.

Gruden called the process a "double-edged sword" for the Raiders, saying if they had re-signed Mack and Cooper, who is due a new contact next year, they would not have been able to pull off this offseason's haul.

"We made some trades a lot of people didn't like last year, but it was all part of the assembly process," Gruden said.

"It was hard to say goodbye to Cooper and Mack. We picked up some draft picks. We also picked up some space to allow us to sign players, so that was the plan. Whether it's right or wrong, we'll find out."